American journal of epidemiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparability of skin screening histories obtained by telephone interviews and mailed questionnaires: a randomized crossover study.
The comparability of information collected through telephone interviews and information collected through mailed questionnaires has not been well studied. As part of the first phase of a randomized controlled trial of population screening for melanoma in Queensland, Australia, the authors compared histories of skin examination reported in telephone interviews and self-administered mailed questionnaires. A total of 1,270 subjects each completed a telephone interview and a mailed questionnaire 1 month apart in 1999; 564 subjects received the interview first, and 706 received the mailed questionnaire first. ⋯ Missing data were less frequent for interviews (0.5%) than for mailed questionnaires (3.8%). Costs were estimated at A$9.55 (US$6.21) per completed interview and A$3.01 (US$1.96) per questionnaire. The similarity of results obtained using telephone interviews and mailed questionnaires, coupled with the substantially higher cost of telephone interviews, suggests that self-administered mailed questionnaires are an appropriate method of assessing this health behavior.
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Clinic-based studies suggest that sleep-disordered breathing (SDB) is associated with glucose intolerance and insulin resistance. However, in the available studies, researchers have not rigorously controlled for confounding variables to assess the independent relation between SDB and impaired glucose metabolism. The objective of this study was to determine whether SDB was associated with glucose intolerance and insulin resistance among community-dwelling subjects (n=2,656) participating in the Sleep Heart Health Study (1994-1999). ⋯ Relative to subjects with a respiratory disturbance index of less than 5.0 events/hour (the reference category), subjects with mild SDB (5.0-14.9 events/hour) and moderate to severe SDB (> or =15 events/hour) had adjusted odds ratios of 1.27 (95% confidence interval: 0.98, 1.64) and 1.46 (95% confidence interval: 1.09, 1.97), respectively, for fasting glucose intolerance (p for trend < 0.01). Sleep-related hypoxemia was also associated with glucose intolerance independently of age, gender, body mass index, and waist circumference. The results of this study suggest that SDB is independently associated with glucose intolerance and insulin resistance and may lead to type 2 diabetes mellitus.